Process of manufacturing sulfuric anhydrid.



nof'reenes.

UNITED STATES l Patented June 2, 1903.

PATENT OFFICE.

PROCESS OF MANUFACTURING SULFURIC ANHYDRID.

SPECIFICATION formingpart of Letters Patent No. 729,735, dated June 2,1903.

Application filed April 1,1901 Serial No. 53,916. (No specimens.)

To It whom, it may concern.-

Be it known that we, ADOLF CLE M and WILHELM HASE NBACH, subjects of theEmperor of Germany, and residents of Mannheim, Germany, have inventedcertain new and useful Improvements in Processes of ManufacturingSulfuric Anhydrid, of which the following is a specification.

This invention relates to an improvement in the process described in thespecification forming part of the application for United States LettersPatent of December 31, 1901, Serial No. 690,133, for improvements in themanufacture or production of sulfuric anhydrid and means to be employedtherein, the present invention consisting in the substitution for ferricoxid by copper oxid, chrome oxid, or a mixture of these oxids or thesulfates formed thereby, said oxide or their sulfates being used ascontact substances and filtering substances for the hot roaster-gases,consisting of sulfurous acid, air, dust out of the burned ore, andpossibly traces of arsenic.

The invention is carried out into practice by first leading the hotroaster-gases over copper oxid or chrome oxid or mixtures of these oxidsor the sulfates formed thereby, then causing them to pass a filter ofporous substances, as fibrous or felted fabrics of acid-proof andfireproof material-esuch as pumice-stone, asbestos, and the like-andfinally leading them over or through a platinum contact substance, asfully described in the specification forming part of the abovecitedprior patent.

We claim 1. The herein-described process of manufacturing sulfuricanhydrid by first leading hot roaster-gases over a mixture of the oxidsof copper and chromium then causing them to pass through a filter ofporous substances and finally bringing them in contact With platinumcontact substance as and for the purpose set forth.

2. The herein-described process of manufacturing sulfuric anhydrid byfirst leading hot roaster-gases over the oxids of copper then causingthem to pass through a filter of porous substances and finally bringingthem into contact with platinum contact substance substantially as andfor the purpose set forth.

In testimony whereof We have signed our names to this specification inthe presence of two subscribing witnesses.

ADOLF OLEMM. WILHELM HASENBAOI-L Witnesses:

H. W. HARRIS, A. GRUMBAD.

